What term describes a language pattern where a client invents new and meaningless words?

The term that best describes a language pattern where a client invents new and meaningless words is "neologism." This concept refers to the creation of new terms or phrases that are not recognized or understood by others. Neologisms are often seen in certain psychological conditions, such as schizophrenia or other thought disorders, where individuals may create unique words that hold personal significance but lack meaning in standard language.

Understanding neologisms is important as they can indicate underlying thought processes and cognitive functioning. This recognition can assist mental health professionals in diagnosing and identifying relevant treatment strategies for clients who may demonstrate this speech pattern. Other terms, while related to speech and communication, do not specifically align with the invention of new words. For instance, perseveration refers to the repetition of a thought or response, pressured speech indicates an increase in the rate of speech that may be difficult to interrupt, and tangential speech represents a disorganized train of thought where the speaker veers off-topic. Each of these has its own distinct characteristics that do not involve the creation of new, meaningless words.